Guilherme Freitas

I am a PhD Candidate in Economics at the California Institute of Technology.
You can find my contact information and much more in my CV.
I'm interested in a range of theoretical and applied problems in
mechanism/market design,
education,
environmental economics
and microeconomics in general.
You might want to check out
my research
or my teaching resources and links.

Research

Monitoring Costs and the Management of Common-Pool-Resources (Job Market Paper)

Abstract.
We lay down a model of a fishery and analyze the outcomes of a program of
individual tradable quotas (ITQs) when quota enforcement is costly and
imperfect. In this setting, decisions about enforcement level should not be
dissociated from other design decisions --- like the total quota available or
its initial distribution. To support those design decisions, we provide an
extensive analysis of ITQ equilibria and full comparative statics for
steady-state equilibria. To the best of our knowledge, this is the first
time this analysis is carried out.

We also provide an extension of the full-compliance result that states that
an ITQ program leads to an efficient use of the fish stock. Relaxing the
assumption of full compliance, we present a principal-agent model where the
principal is a fishery owner and the agents are the fishermen. The principal
chooses how to allocate quota among the fishermen and how much to invest in
monitoring to set the enforcement level. Agents choose how much fish to
catch in face of their quota and the enforcement level. We show that, while
the first-best outcome is not incentive-compatible, second-best outcomes can
be implemented by an ITQ program if, and generically only if the expected
violation fines depend on catch and quota only through absolute violations.

Finally, we establish sufficient conditions for fishermen's preferences over
small changes in enforcement to be single-peaked. We emphasize that even
though the distribution of quota endowments does not affect the attained ITQ
equilibrium directly, it may affect outcomes indirectly if fishermen can
influence the process that sets the cap or enforcement levels --- with or
without quota trading. PDF.

Abstract. We consider the problem of assigning shares of a imperfectly
divisible resource when preferences are dichotomous. One such problem is
the problem of assigning bundles from a finite set of indivisible objects
to a finite set of agents. When preferences are dichotomous, mech- anisms
that satisfy voluntary participation only require agents to report a set of
acceptable bundles/shares. We characterize strategyproof mechanisms for
such problems and provide a mechanism that is utilitarian-efficient,
strategyproof and envy-free, thereby showing that impossibilities like the
ones pointed out by Kojima (2009) can be circumvented if we assume
dichotomous preferences. We also show that, unlike in the assignment
problem with dichoto- mous preferences of Bogomolnaia and Moulin (2004),
the existence of a Lorenz-dominant assignment is not guaranteed. We analyze
real-world difficulties involved in using efficient mechanisms, both from a
computational and a strategic point of view. In particular, we show that
utilitarian-efficient mechanisms require computations that can have running
times that are exponentially long in the number of agents, but we point out
that some classes of problems can be solved faster. We also show that
agents with general preferences facing a mechanism that is strategyproof
and efficient in the dichotomous domain might have an incentive to mis-
report their acceptable shares/bundles, and in that case, the only
profitable deviation is to report a smaller set of acceptable
shares/bundles. PDF.

Voting with Common Values in Committees (with Matias Iaryczower and Matt Shum, in progress [abandoned 2015])

Teaching

I have taught the Mathcamp at the Division of the Humanities and Social
Sciences at Caltech. The course reviews some of the most useful mathematical
tools for the first-year PhD students at the division. Check the Syllabus, some code for computational sessions in the lab, and, most
important, the problem set.

As the TA for an undergraduate course in Power Systems at Caltech,
I wrote some quick notes
on the basics of convex optimization and Karush-Kuhn-Tucker conditions.
They are not very polished,
but they are a good complement to more rigorous texts
(mentioned in the final section),
providing intuition and some useful hints.

I have worked as a volunteer tutor for School On Wheels, an NGO that provides one-one-one tutoring assistance for homeless children. If you believe that
education is the way to provide opportunity to everyone, check them out! You
can help in many ways: tutoring and donating are just two out of many options.
For example, besides my tutoring activity, I also participated on a workshop
where we discussed different issues in the education of homeless children. I
talked about how to enrich the solution of math problems with an inquisitive
trial-and-error approach. Here are the slides of the talk. And if you are teaching
multiplication, it doesn't hurt to use a pretty multiplication table.

I am always happy to discuss ideas for improving education at all levels. A
sample of topics on education that have recently caught my attention are:
evaluation methods that give good feedback to our students and encourage
learning; ways of using measurements, experiments and computation to aid middle
and high-school students' understanding of mathematical concepts; and a
curriculum for economics majors in college.